A novel interface engineering strategy is proposed to simultaneously achieve superior irradiation tolerance, high strength, and high thermal stability in bulk nanolayered composites of a model face‐centered‐cubic (Cu)/body‐centered‐cubic (Nb) system. By synthesizing bulk nanolayered Cu‐Nb composites containing interfaces with controlled sink efficiencies, a novel material is designed in which nearly all irradiation‐induced defects are annihilated.